As a technique for depositing a film with a favorable film thickness distribution on a substrate surface by using a target smaller than the substrate size, widely used is an oblique-incidence rotation sputter technique in which a target is arranged obliquely to the substrate (for example, Patent Document 1).
A magnetron sputter technique has the following problem in the case of depositing an insulating film on a substrate.
In the magnetron sputter technique, particles in plasma generated near a target are made incident to the target, and particles are ejected from a target due to the incidence. In this process, some of the ejected particles become negative ions. These negative ions are accelerated in a direction opposite to the target (namely, a direction toward the substrate) by an electric field formed on a surface of the target.
Such accelerated negative ions damage a film on the substrate in some cases. This problem is particularly noticeable in the case where the target is an insulator. For this reason, for a process requiring particularly fine film quality control, the oblique-incidence rotation sputter technique requires a target to be shifted and arranged away from a substrate in a direction parallel to the substrate surface or to be arranged at a smaller inclination angle to the substrate (in other words, in a state where the target and the substrate are more parallel to each other) so that a projection plane projected in a direction normal to the target at the center toward a substrate surface can be located outside the substrate surface.